Key points from article :
315,000 US adults asked about their activity at four different points in their lives.
At ages 15-18 years, 19-29 years, 35-39 years and 40-61 years.
Consistent exercisers 29% to 36% reduced mortality during 20-year period.
The more people exercised, the greater their risk reductions.
Similar results in those who increased their exercise levels after their 40s.
Including reductions in heart disease and cancer risk.
You can still benefit if you start becoming active in your 40s and 50s.
The study was Published in JAMA Network Open.
